Device for the formation of a travelling shed in looms



p 196,7. QR. H: ROSSMANN 3,342,218

7 DEVICE FOR THE FORMATION OF A TRAVELLING SHED IN LOOMS Filed March 22, 1965 V V 2 Sheets-Sheet 1 Tag-.1. i

NEYS

19, 1957 R. H. ROVSSMANN 3,342,218

I DEVICE FOR THE FORMATION OF A TRAVELLING SHED IN LOOMS Filed March 22, 1965 E. I Y Li I L/Z 2 Sheets-Sheet 2 ATTORNEYS United States Patent 3,342,218 DEVICE FOR THE FORMATION OF A TRAVELLING SHED IN LOOMS Rudolf H. Rossmann, Gauting, near Munich, Germany, assignor to U.T.L. Incorporated, Scranton, Pa. Filed Mar. 22, 1965, Ser. No. 441,762 14 Claims. (Cl. 139-12) The present invention relates to a device for the formation of a travelling shed in looms, and more particularly to a device of this kind wherein the heddles or healds of the upper and lower sheds of each half shed wave are combined, preferably in three separate groups.

In the formation of travelling sheds, such as are necessary, for example, with looms wherein a succession of shuttles is simultaneously moving through the warp in each individual shed at a particular moment, some of the warp threads are positioned right up and some are right down, while the others are in motion. This means that some threads move upwards and some move simultaneously downwards as the sheds are moving like waves through the warp.

This would mean for the weaving of a plain weave that, in order to form a travelling shed correctly, only one thread from each shed would make the same movement as the corresponding threads of the other sheds. If, for example, twelve individual travelling sheds are provided over a weaving width, the use of normal shafts of heddles will only allow twelve individual warp threads to be combined on each shaft. If, for example, a hundred threads are located in each individual shed and within the upper shed, and a hundred within the lower, 2x100 heddle shafts must be used.

Attempts have, therefore, been made with looms to produce a wave-like travelling shed in the form of waves composed of steps, using reciprocating movements for the groups of heddles. The movement of the heddle groups, in this case, is effected not by ordinary heddle shafts known from conventional shed formation but by means of special cams, specifically related to each individual group of heddles. This known loom is, therefore, relatively complicated and liable to breakdowns. Moreover, the individual warp threads are differently tensioned, thus causing an untidy shed formation and an unsatisfactory run of the shuttles.

It is the object of the present invention to provide a device for the formation of a travelling shed in looms, wherein the disadvantages of hitherto known structures are eliminated.

It is a further object to provide such a device wherein the heddles or healds of the upper and lower sheds of each half shed wave are combined.

It is yet another object to provide a device of this kind wherein the heddle groups of the travelling shed waves are secured to a common shaft frame, the individual shafts reciprocating out of phase according to the number of heddle groups selected.

According to one of the major features of the invention,a device is provided for the formation of travelling sheds in looms, wherein successive travelling waves of warp threads are formed by a phase-displaced, grouped reciprocating movement of the warp-thread heddles, forming upper and lower sheds, a shuttle running in the loops of said warp threads. The novel feature resides in that the heddles of the upper and the lower sheds of each half shed wave are combined into groups, preferably in three separate groups, and that the heddle groups of all the travelling shed waves which reciprocate in phase are secured to a common, straight shaft frame, the individual shafts reciprocating out of phase, according to the number of groups selected.

Since in each case the warp threads of the upper and lower sheds are brought together on the same shaft, it is possible to produce a plurality of wave-like travelling sheds even with a relatively small number of shafts, affording free passage for the shuttles, in approximately the same manner as with sheds formed by stepless waves.

According to another important feature of the invention, the groups of upper and lower-shed heddles, which are spaced at a distance of half a wave, are each secured to a common shaft frame. Also, the individual shaft frames can be reciprocated in the previously determined phase-displacement pattern by means of angularly displaced eccentric cams secured to a common drive shaft, preferably at both ends. This reciprocating movement of the shaft frames is preferably sinusoidal.

It is yet another inventive feature that, in the case of a substantially vertical warp-thread feed-in, the shafts are moved to and fro substantially in a horizontal direction. This results in an exceptionally favorable'design, as has been described and illustrated in applicants co-pending US. patent application Ser. No. 407,503, filed Oct. 29. 1964, now Patent No. 3,292,664, and entitled, Loom Arrangement.

The warp beam can be mounted approximately in the center of the lower frame part so that the warp threads can be led, from this beam, along the front side of the machine, and in an upward direction. This upward path is followed by a short section passing in a substantially horizontal direction, to allow for the operation of a Warpthread control mechanism. The threads are being passed through a thread tension compensating device which is within the field of view of the operator. Finally, the warp threads pass approximately vertically upwards through a region where means are located for forming the fabric.

With approximately horizontally disposed heddles, the

reed performs up-and-down reciprocating movements,

beating up the weft threads upwardly against the fell of the cloth. The woven cloth is advanced in an approximately vertical, upward direction and. is wound onto a beam positioned in the upper part of the machine frame. As a result, the operator can easily supervise both the warp and the weft threads, as well as the cloth itself, on the same machine side.

According to a further feature of the device according to the invention, the warp threads, in their reciprocating motion for shed formation, are held under tension by a slack compensating device provided for each individual group of heddles.

Still a further feature of the present invention relates to a stepped shaft which is synchronized with the reciprocating movement of the heddle shafts. The individual, eccentric, cylindrical stepped sections of the shaft are displaced angularly in relation to each other in such a way that the change in the tension of the individual warpthread groups, caused by the successive travelling shed formation, is always compensated for. It will be explained later that each stepped section is associated with one warpthread group from the upper and the lower sheds. The compensation results in the threads of the travelling stepped waves being held under uniform tension at all points so that reliable shuttle movement is made possible.

The points where the weft threads are beaten up form a straight and even line, thus preventing the danger of warp streakiness at the edges of adjacent warp-thread groups.

Since the warp threads are tensioned twice per shedding cycle, the stepped shaft must be driven twice as fast as the eccentric cams of the shaft drive, according to yet another inventive feature. In addition, the stepped shaft can be driven in the reverse direction as compared with the direction of the warp-thread feed, in order to effect a braking of the warp threads.

Other objects and advantages of the invention will be readily appreciated and more fully understood with reference to the following detailed description, when considered with the accompanying drawings, wherein FIG. 1 is a partly sectional side view illustrating the mutually phase-displaced arrangement of the shaft frames in a loom of the kind described, as well as the warpthread tension compensating device, according to the invention, also shown in FIG. 3 along section line 11;

FIG. 2 is a partly sectional, partial top view of the lefthand section of FIG. 1, showing, as a matter of example, 6 cams and 6 frames;

FIG. 3 is a side view, taken along line 3-3 of FIG. 2, and corresponding to the left-hand portion of FIG. 1 where some of the repetitious elements have been omitted for the sake of clarity;

FIG. 4 is a somewhat enlarged plan view of a stepped tension compensating shaft according to the invention;

FIG. 5 is a sectional view, taken along line 5-5 of FIG. 4;

FIG. 6 is a schematic illustration of the formation of travelling shed waves by individual groups of heddles or healds, in the device according to the invention, as illustrated in FIGS. 1 through 5; and.

FIG. 7 shows, in a somewhat schematic manner, the allocation of the individual heddle groups to the corresponding common shaft frames.

Before going into structural details of the device according to the invention for the formation of travelling sheds, the shed-wave formation will be explained with reference to FIG. 6. The complete length of a cycle of the travelling Wave denoted L is divided into six groups, equal to L/ 6 lengths each, and denoted 1a, 2a, 3a, 4a, 5a and 6a. FIG. 6 shows a complete wave, i.e., a series of movements constituting a unit, to be composed of six units, three upper and three lower. Six frames are required to perform a repeat and a repeat constitutes a wave length. The number of groups arranged on each harness frame consitute the number of complete wave length being formed at all times during weaving. In order to travel longitudinally from the left to the right in the schematically indicated wave W, individual thread groups, corresponding to the sections 1a 6a, must be led out of their respective positions, namely in transversal direction, as indicated by the small vertical arrows.

It will be clear from this illustration that, for example, Warp groups 1a, 2a, 3a, as well as subsequent groups 1b, 2b, 3b perform a simultaneous downward movement at the indicated instant. At the same time, thread group 4a, 5a, 6a as well as the preceding groups 4, 5, 6 make a simultaneous upward movement. It is also shown how each separate half-wave runs, e.g., from 1a to 4a, or from 4 to 1b; in the next section, from 4a to the starting point of another half-wave, namely 16, or from 1b to 411, etc. Depending on the position of the wave, group 1a may be moving downward, group 211 may be stationary preparatory to beginning an upward movement, and group 3a may be moving upward.

It is further apparent from the foregoing that groups 1a and 1b, 2a and 2b, 3a and 3b, as well as 40 and 4b, 5a and 5b, 6a and 6b, i.e., groups which are at a distance of half a shed-wave from each other, denoted L/2, are not only carrying out their respective upward and downward (transversal) movement at the same time but are also at the same respective shed height. It is, according to the invention, possible to combine these groups on a common support shaft. For the formation of a travelling shed, therefore, not twelve but only six individual shafts are needed with the arrangement according to the invention. It should be noted that FIG. 7 also identifies groups 1d, 2d, 3d, as well as 20, 3c, 40, 5c and 6c, to follow those appearing in FIG. 6, as will be explained somewhat later.

FIGS. 1-3 show the structure of the device according to the invention, including a drive shaft 10 having thereon a plurality of eccentrically arranged cams; in the present, exemplary embodiment, six cams are shown, numbered 11, 12, 13, 14, and 16. By conventional annular follower means, the cams are connected to respective rods 21, 22, 23, 24, and 26 of which some are broken away in FIG. 1 for a clearer illustration. Again by conventional joints, linkages or the like, each connecting rod is attached to a shaft frame; here, again, six elements are shown, namely 31, 32, 33, 34, and 36.

FIG. 6 has, on its left-hand side, the frame designations added thereto so as to indicate the respective motions performed by said frames. FIG. 7, furthermore, shows all six frames 31-36, with a pair of respective connecting rods 21-26 pivotally attached thereto. Equal groups of heddles or healds are located in each frame, at a distance of half a shed-wave, as will be clear from a comparison of FIGS. 6 and 7. FIG. 1 shows how groups of warp threads 44 pass through the groups of heddles 40.

The six frames 31-36 operate in common and are moved simultaneously, in a displaced phase, as indicated in FIG. 7 by the small arrows which, of course, correspond to those already discussed in connection with FIG. 6. The reciprocation is effected in a substantially horizontal direction, as shown in FIG. 1. It should be noted that supports for the frames have not been illustrated in the figures.

For a plain weave or cloth it is sufficient in this case to have the shafts and frames 31-36 carry out a simple phasedisplaced sinusoidal movement. This can, for example, be obtained by means of the eccentric cams 11-16 illustrated herein, or by way of cranks, in which case the shafts operate without any impact. In case of six cams, these are offset with respect to the common shaft 10 by 60 degrees each, as is best seen in FIG. 3. If another equal number is used, the angular displacement would be changed accordingly (e.g., degrees for eight cams and frames).

The heddles 40 are located in the same sections of frames 31 and 34 (see thread groups 1a and 4, respectively, shown in FIG. 6 to move within the same L/6 shed-wave, but in opposite directions), in frames 32 and 35, as well as in frames 33 and 36. In effect, FIGS. 1 and 3 clearly illustrate this arrangement, cam 11 with its rod 21 and the frame 31 attached thereto being the foremost (that is, toward the right-hand side of FIG. 1), while frame 34 is the rearmost among the six frames.

For a description of FIGS. 4 and 5, it should be understood that the warp threads 44 of each group in the shed formation, in which the individual frames 31-36 reciprocate in parallel directions, are most strongly tensioned in the outermost positions of the respective shafts (positions of frames 31 and 34 in FIGS. 1 and 2), whereas in the intermediate positions, like those shown for frames 32, 33, 35 and 36, they are relatively slack.

It has already been shown in FIG. 1 that the groups of threads 44 are guided over corresponding sections of a tensioning roller or shaft 50. The conventional means for driving this shaft in synchronization with the shaft 10 has not been illustrated. The individual, eccentrically displaced roller sections are mounted on a common shaft which rotates at twice the speed required for shaft 10 when set up in the illustrated fashion for the healds 40 of the frames 31-36. The mean tangent of shaft 60 is centered under healds 40.

Either rotating or oscillating action is possible with the present invention, i.e., both may be the case. While shaft 60 rotates, the rollers 50 can either rotate, in which case the rollers are rigidly fastened on the shaft, or they may rotate on the shaft, i.e., they would then stand still, and merely oscillate.

By this novel arrangement, the shortening and lengthening of the threads 44 is compensated for during the reciprocation of the frames 31-36. During a complete shedding cycle, the threads 44 are tensioned twice, once at the top and once at the bottom. If the distance by which the threads in the intermediate positions become slackened as compared to their lengths when at maximum tension, in the upper and lower or outermost positions, is given as x, the tensioning rollers 50 on shaft 60 are displaced by x/Z in relation to the axis of this shaft, as has been shown in FIG. 5.

According to the invention, the shaft 60 with the stepped, eccentrically supported roller sections 50 is made in such a way that the mantle of shaft 60 has therein a number of longitudinal grooves 61 uniformly distributed and corresponding to the number of thread groups (e.g., six) selected for the particular shed-Wave length. The tension rollers 50 are cylindrical tube sections of a length corresponding to the width of the thread groups (e.g., 1a 6a). Keys or like members 62 are inserted in circumferentially successive grooves Within each roller section 50. The sectional view of FIG. 5 shows how a roller 50 is spaced apart from shaft 60 by a member 62 inserted in one of the grooves 61, producing thereby the eccentric positioning of that roller. Appropriate, preferably loose, thread-guide discs 63 may be inserted between consecutive roller sections 50 to insure safe guidance of the threads 44 on their respective rollers.

The direction of rotation of the stepped shaft 60 is preferably selected in such a way as to provide a braking effect on the Warp threads 44, i.e., so that the surface of the roller sections 50 moves in a direction opposite to the warp-thread feed. In FIG. 1, this has been indicated by appropriate directional arrows adjacent the threads 44 and the tension compensating device denoted 50.

However, the rollers 50 can also be eccentrically and rotatably mounted on the shaft 60, e.g., on suitable needle bearings (not shown), if no braking effect is required. In this event, the sense of rotation of device 50 can be reversed to be identical with the thread feed direction.

The division of the entire travelling shed wave into six individual groups, according to the exemplary embodiment shown and described, enables sufiiciently fine steps to be obtained for most practical cases. However, any other desired division into even numbers, e.g., eight, ten or more groups, is feasible. A correspondingly larger number of cams, shafts and frames will, of course, be required in this event.

Although the invention has been described and explained on the basis of a plain weave, the device according to the invention can also be used, with slight modifications, for other regular kinds of weave, e.g., a twill weave and the like, without departing from the inventive concept.

The foregoing disclosures relates only to a preferred embodiment of the invention, which is intended to include all changes and modifications of the example described within the scope of the invention as set forth in the appended claims.

What I claim is:

1. A device for the formation of a travelling shed in warp threads of a loom in the form of a travelling wave of predetermined period, comprising, in combination, a plurality of heddles in engagement with the warp threads for forming said travelling shed, a plurality of shaft frame means each containing a predetermined number of heddles combined into a plurality of groups, each of said groups representing corresponding portions of said travelling shed in successive periods thereof, one half of said plurality of shaft frame means arranged to form an upper portion of said travelling shed, the other half of said plurality of shaft frame means arranged to form a lower portion of said travelling shed, control means for reciprocating each shaft frame means over a predetermined distance, each of said shaft frame means reciprocable out of phase with respect to each other as a function of the number of said plurality of heddle groups, the plurality of heddle groups of each shaft frame means being connected for reciprocation in phase to a respective one of said control means, and driving means for said reciprocating means.

2. A device as defined in claim 1, wherein the number of heddle groups within one period and in each shed portion is three and that of the shaft frames is six, the control means including control members displaced in a phase delay correspondingto an angle of 60 degrees.

3. A device as defined in claim 1, wherein the heddle groups of the upper and lower shed portions move with a phase delay of a half period.

4. A device as defined in claim 1, wherein the control means includes angularly displaced eccentric cams on a common drive shaft, one cam for each shaft frame.

5. A device as defined in claim 4, further comprising at least one linkage means interconnecting each cam with a respective shaft frame.

6. A device as defined in claim 1, wherein the Warp threads extend substantially in the vertical direction, the reciprocating movement of the shaft frames being substantially in a horizontal plane.

7. A device as defined in claim 1, further comprising slack compensating means disposed in the path of the Warp threads and having separate tensioning members for each heddle group.

8. A device as defined in claim 7, wherein the slack compensating means includes a shaft rotating at twice the speed of the driving means, the tensioning members being carried on the shaft for free rotation.

9. A device as defined in claim 8, wherein the direction of rotation of the shaft is opposite to the direction of feed of the warp threads.

10. A device as defined in claim 7, wherein the driving means includes a rotating drive shaft, said slack compensating means includes a tensioning shaft driven in synchronization with the drive shaft, the latter being operatively connected with angularly displaced control members forming part of the control means, and the tensioning shaft carries tensioning members corresponding in number to that of the control members and being correlated therewith.

11. A device as defined in claim 10, wherein the tensioning shaft comprises a number of longitudinal grooves formed therein corresponding to the number of the shaft frames, the tensioning members being in the form of cylindrical tube sections surrounding the tensioning shaft, and guide members interposed between each groove and one tube section to provide an eccentric journaling for the tube sections.

12. A device as defined in claim 11, further comprising thread-guide discs interposed between adjacent pairs of tube sections.

13. A device as defined in claim 10, further comprising means for rotatably journaling the tensioning members on the tensioning shaft.

14. A device as defined in claim 13, wherein the journaling means includes needle bearings.

References Cited UNITED STATES PATENTS 889,971 6/1908 Salisbury 139-42 2,845,093 7/1958 Dietzsch et al. 139--12 3,009,485 11/1961 Jackson et a1. 13925 FOREIGN PATENTS 1,237,034 7/1960 France.

MERVIN STEIN, Primary Examiner.

H. S. JAUDON, Assistant Examiner. 

1. A DEVICE FOR THE FORMATION OF A TRAVELLING SHED IN WRAP THREADS OF A LOOM IN THE FORM OF A TRAVELLING WAVE OF PREDETERMINED PERIOD, COMPRISING, IN COMBINATION, A PLURALITY OF HEDDLES IN ENGAGEMENT WITH THE WRAP THREADS FOR FORMING SAID TRAVELLING SHED, A PLURALITY OF SHAFT FRAME MEANS EACH CONTAINING A PREDETERMINED NUMBER OF HEDDLES COMBINED INTO A PLURALITY OF GROUPS, EACH OF SAID GROUPS REPRESENTING CORRESPONDING PORTIONS OF SAID TRAVELLING SHED IN SUCCESSIVE PERIODS THEREOF, ONE HALF OF SAID PLURALITY OF SHAFT FRAME MEANS ARRANGED TO FORM AN UPPER PORTION OF SAID TRAVELLING SHED, THE OTHER HALF OF SAID PLURALITY OF SHAFT FRAME MEANS ARRANGED TO FORM A LOWER PORTION OF SAID TRAVELLING SHED, CONTROL MEANS FOR RECIPROCATING EACH SHAFT FRAME MEANS OVER A PREDETERMINED DISTANCE, EACH OF SAID SHAFT FRAME MEANS RECIPROCABLE OUT OF PHASE WITH RESPECT TO EACH OTHER AS A FUNCTION OF THE NUMBER OF SAID PLURALITY OF HEDDLE GROUPS, THE PLURALITY OF HEDDLE GROUPS OF EACH SHAFT FRAME MEANS BEING CONNECTED FOR RECIPROCATION IN PHASE TO A RESPECTIVE ONE OF SAID CONTROL MEANS, AND DRIVING MEANS FOR SAID RECIPROCATING MEANS. 